Ultrafiltration is a form of filtration that uses membranes
to preferentially separate different fluids or ions. Ultrafiltration
also uses a membrane that is partially permeable to perform
the separation, but the membrane's pores are typically much
larger than the membrane pores that are used in reverse osmosis.
Ultrafiltration is most commonly used to separate a solution
that has a mixture of some desirable components and some that
are not desirable.
Ultrafiltration is capable of concentrating bacteria, some proteins,
some dyes, and constituents that have a larger molecular weight
of greater than 10,000 daltons. Ultrafiltration is only somewhat
dependent upon the charge of the particle and is much more concerned
with the size of the particle. Ultrafiltration is typically
not effective at separating organic streams.